Netbotz appliances have "Guest" account that does not require a password. This account is disabled or given a privilege set of none by default. When you log in through the web or Advanced View, you do not need to enter credentials if the guest account is set with any other rights.

If you look at the guest user account in Advanced View, you will see that "Guest Account = *" If you give this account admin rights, any credentials will allow full access to the Netbotz appliance. This works the same way when ISXC is logging in to the appliance

Resolution:

In order to be able to specify the proper credentials for ISXC to log in to the Netbotz appliance, simply leave the "Guest" account with it's default privileges of none.